Method and apparatus for delivering cement paste into a bone cavity

ABSTRACT

A technique for simultaneously forming a plurality of paste filled tunnels. The plurality of paste filled tunnels are connected to a surgical tube directly or indirectly and emptied one after another, until a desired amount of the paste is injected into a bone cavity, organ or a tissue via the surgical tube. The paste may be a bone cement paste, a drug powder paste, viscous fluid or gel. The injected bone cement paste will set in the bone cavity to act as a medical implant.

CROSS-REFERENCE TO RELATED APPLICATION

This patent application claims the benefit of U.S. Provisional PatentApplication No. 61/479,421, filed Apr. 27, 2011.

FIELD OF THE INVENTION

The present invention is related to a technique for simultaneouslyforming a plurality of cement paste filled tunnels which are adapted tobe connected to a surgical tube. The present invention is also relatedto a method for injecting a cement paste into a bone cavity, in whichthe cement paste will set to act as a medical implant.

BACKGROUND OF THE INVENTION

A common method for delivering a cement paste (or any other highlyviscous paste) into a bone (or other tissue or organ of a diseasedsubject) cavity by a minimally invasive procedure is by pressing thepaste into the cavity through a thin tube percutaneously inserted intothe cavity. To fill in a bony cavity, PMMA and calcium-based cements aremost commonly used. The cement paste is generally prepared by mixing asolid powder component with a liquid component (setting solution) at aproper ratio to form a paste. The mixed paste is set (hardened) andstarts to gain its strength generally within minutes or tens of minutes,depending on the setting time of the formula being used.

To minimally invasively transport the cement paste into the cavitythrough a thin tube, conventionally, a syringe type device is used,wherein the mixed cement paste is stored in a container (reservoir) andpushed by a piston or a plunger through a small exit connected to a thintube that has been percutaneously inserted into the bone cavity. Sincethe cross-sectional areas of the container and the exit are largelydifferent (For example, the cross-sectional area of the container of aconventional 10 c.c. syringe is larger than that of its exit by about 60times; and the cross-sectional area of the container of a conventional20 c.c. syringe is larger than that of the exit by about 100 times), alarge pressure is often implemented in order to push the cement out ofthe exit. However, larger pressures require more complicated designs inthe delivery tool as well as higher costs. This problem becomesespecially serious in delivering a highly viscous paste, such as PMMAand calcium-based cement. Although a more dilute paste prepared with ahigher liquid/powder ratio may make the paste flow and be pushed throughthe small exit more easily, unfortunately, a dilute paste almost alwaysleads to poor material properties. This is a big dilemma in this field.Theoretically, using a thin container (reservoir) with a diametersimilar to that of the thin surgical tube (or connecting tube) mayovercome the problem caused by the large difference in cross-sectionalarea between container and its exit. Practically, however, in so doing,an extremely long container is required. For example, to minimallyinvasively deliver a cement paste of 5 cc in volume through a containerwith an inner diameter of 1 mm would require a container of more than 6meters in length; and to deliver a 10 cc cement paste through the samecontainer would require a container longer than 12 meters! (A plunger ofthe same length is also required to drive the paste all the way to thecontainer exit) This kind of length is practically impossible for anykind of surgery. Furthermore, even if an extremely long, thin containeris used, it would be practically impossible to transport the mixedcement paste into this thin container. When a regular syringe is used,the large cross-sectional difference-induced problem still remains inthe transportation of the paste from the syringe into the thincontainer.

Another primary problem with the conventional syringe-type cementdeliverer is that a larger pressure does not guarantee a more efficientdelivery. In many cases (for example, for most calcium-based cements),the opposite is true. This is because that, before being fully hardeneddue to the reaction between powder and liquid, the cement paste is stilla solid-liquid two phase material. Under pressure, the liquid phasetends to separate from the solid phase. Since the greatest pressuregradient occurs at the exit (thin neck) region, the liquid tends to flowout of the exit at a higher speed than the solid. Due to thissolid-liquid separation effect, the cement paste coming out of thecontainer at the early stage has a higher-than-desired liquid/powderratio, causing properties of the cement to degrade. On the other hand,the cement remaining in the container, especially at the later stage,has a lower-than-desired liquid/powder ratio (because the lower-densityliquid continues to be squeezed out of the container) and becomesdifficult to flow out of the exit.

SUMMARY OF THE INVENTION

A primary object of the present invention is to provide a method andapparatus for injecting a cement paste into a bone cavity or like, inwhich the cement paste will set and act as an implant. Morespecifically, the present invention provides a technique forsimultaneously forming a plurality of cement paste filled tunnels whichare adapted to be connected to a surgical tube. According to oneembodiment of the present invention the plurality of cement paste filledtunnels are connected to the surgical tube and emptied one-by-one,whereby a desired amount of cement paste is injected into the bonecavity.

Another object of the present invention is to provide a method andapparatus for injecting a drug powder paste, viscous fluid or gel into asite needing a treatment. The drug powder paste may be formed by anon-soluble drug powder dispersed in a liquid medium such as water, oiland any pharmaceutically acceptable liquid carrier. The viscous fluidfor example may be an oil or a polymeric liquid with or without a drugdissolved or dispersed therein. The gel for example may be collagen,gelatin, or a bio-polymeric gel-like material with or without a drugdissolved or dispersed therein. The drug for example can be ananti-cancer agent, bone growth factor, neuron growth factor, or hormone.More specifically, the present invention provides a technique forsimultaneously forming a plurality of tunnels filled with a drug powderpaste, viscous fluid or gel, which are adapted to be connected to asurgical tube. According to one embodiment of the present invention theplurality of filled tunnels are connected to the surgical tube andemptied one-by-one, whereby a desired amount of the drug powder paste,viscous fluid or gel is injected into the site needing a treatment forexample a vertebra, bone cavity, an organ such as brain and liver, or atissue such as a joint, blood vessel, and muscle.

In order to accomplish the aforesaid objects of the present invention, afilling apparatus constructed according to the present inventioncomprises a plurality of parallel tunnels formed in a longitudinal bodyand in a longitudinal direction of said body; a filler reservoir havingan exit end adapted to be in fluid communication with said plurality ofparallel tunnels; and optionally a driver for driving a filler containedin said reservoir into said plurality of parallel tunnels via said exitend, wherein the cross-sectional area of said exit end is less thanabout 5 times of a total cross-sectional area of said plurality ofparallel tunnels.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a tunnel-type receiver for cement paste to simultaneouslyflow into tunnels of the receiver according to one embodiment of thepresent invention.

FIG. 2 shows a cross-section view of the tunnel-type receiver shown inFIG. 1, a cement paste container and a piston constructed according tothe present invention, and a partially enlarged cross-sectional viewthereof, wherein a cement paste is pushed from the piston tosimultaneously flow into tunnels of the receiver.

FIG. 3 shows a cross-section view of the tunnel-type receiver filledwith cement paste, a connecting tube and a surgical tube constructedaccording to the present invention, and a partially enlargedcross-sectional view thereof, wherein a cement paste is transferred fromthe tunnel into the connecting tube and surgical tube.

FIG. 4 shows a cross-section view of the tunnel-type receiver filledwith cement paste, and a connecting tube (a surgical tube) constructedaccording to the present invention, wherein a cement paste is deliveredfrom the tunnel into the connecting tube (the surgical tube) with aplunger.

FIG. 5 shows a tube-type receiver for cement paste to simultaneouslyflow into receiving tubes of the receiver according to one embodiment ofthe present invention.

FIG. 6 shows a cross-section view of the tube-type receiver shown inFIG. 5, a cement paste container and a piston constructed according tothe present invention, and a partially enlarged cross-sectional viewthereof, wherein a cement paste is pushed from the piston tosimultaneously flow into tubes of the receiver.

FIG. 7 shows a cross-section view of the receiving tube filled withcement paste, a connecting tube, an extension tube, and a surgical tubeconstructed according to one embodiment the present invention, wherein acement paste is transferred from the receiving tube into the connectingtube, extension tube and surgical tube.

FIG. 8 shows a cross-section view of the receiving tube filled withcement paste, and a connecting tube (a surgical tube) constructedaccording to one embodiment the present invention, wherein a cementpaste is delivered from the receiving tube into the connecting tube (thesurgical tube) with a plunger.

FIG. 9 shows an annular receiver for cement paste to simultaneously flowinto tunnels of the receiver according to one embodiment of the presentinvention.

FIG. 10 shows a cross-section view of the annular receiver shown in FIG.9, a cement paste container and a piston constructed according to thepresent invention, wherein a cement paste is pushed from the piston tosimultaneously flow into tunnels of the receiver.

FIG. 11 shows a modified annular receiver for cement paste tosimultaneously flow into tunnels of the receiver according to oneembodiment of the present invention.

FIG. 12 shows a cross-section view of the modified annular receivershown in FIG. 11, a cement paste container and a piston constructedaccording to the present invention, wherein a cement paste is pushedfrom the piston to simultaneously flow into tunnels of the receiver.

FIG. 13 is a schematic side view showing that the annular receiver ofthe present invention is connected to a connecting tube (a surgicaltube) with a gun device, wherein the cement pastes filled in the tunnelsof annular receiver are automatically or semi-automatically deliveredinto the connecting tube (the surgical tube) one after another.

FIG. 14 is a schematic perspective view showing a modified tunnel-typereceiver for cement paste according to one embodiment of the presentinvention.

FIG. 15 shows a schematic perspective view of a modified tube-typereceiver having two cylindrical tube holders, partially enlargedcross-sectional views thereof, and a cross-sectional view of themodified tube-type receiver together with a cement paste container and apiston constructed according to one embodiment of the present invention.

FIG. 16 shows a modified tube-type receiver for cement paste accordingto one embodiment of the present invention.

FIG. 17 shows a modified tube-type receiver for cement paste accordingto one embodiment of the present invention, which has a circular rearend and a square front end.

FIG. 18 shows the modified tube-type receiver in FIG. 17 together withan outlet adapter 51 capped onto the square front end thereof.

FIG. 19 shows a receiver for cement paste counterclockwise rotatablyreceived in an outlet adapter with a ratchet mechanism for deliveringthe cement paste in the receiver according to one embodiment of thepresent invention.

FIG. 20 shows a receiver for cement paste rotatably capped with anoutlet adaptor having a sealing and blocking mechanism according to oneembodiment of the present invention, wherein (a) to (c) show differentembodiments of the sealing and blocking mechanism.

FIG. 21 shows a receiver for cement paste rotatably capped with anoutlet adaptor, wherein a wave-like tack is formed around the surface ofthe receiver and a pair of sliding guides are formed oppositely on aninner wall of the outlet adaptor, whereby the outlet adaptor can move upand down when the outlet adaptor is turned.

DETAILED DESCRIPTION OF THE INVENTION

In the following, a general term “filler” is used to represent thecement paste, and the drug powder paste, viscous fluid or gel.

A filling apparatus constructed according to one embodiment of thepresent invention comprises a plurality of parallel tunnels formed in alongitudinal body and in a longitudinal direction of said body; and afiller reservoir having an exit end adapted to be in fluid communicationwith said plurality of parallel tunnels, wherein a cross-sectional areaof said exit end is less than about 5 times of a total cross-sectionalarea of said plurality of parallel tunnels.

Preferably, said tunnels have an inner diameter of about 1 mm to about10.0 mm and a length of about 10.0 mm to about 300 mm.

Preferably, the cross-sectional area of said exit end is less than about3 times of a total cross-sectional area of said plurality of paralleltunnels, and more preferably about 1.5 to about 1.1 times of a totalcross-sectional area of said plurality of parallel tunnels.

Preferably, said longitudinal body has a multi-tubular structure withsaid plurality of parallel tunnels being formed therein.

Preferably, the apparatus of the present invention further comprises aplurality of receiving tubes, wherein said longitudinal body is a hollowlongitudinal body and said plurality of receiving tubes are received insaid hollow longitudinal body such that said plurality of paralleltunnels are formed in said plurality of receiving tubes.

Preferably, the apparatus of the present invention further comprises twotube holders, wherein each of the two tube holders comprises amulti-tubular structure with a plurality of openings, and the two tubeholders are connected to or one of them is connected to and the otherone is adapted to be connected or both adapted to be connected to twoends of the hollow longitudinal body with said plurality of openings ofthe two tube holders being aligned with one another, such that saidplurality of receiving tubes are mounted in said plurality of openingsof the two tube holders respectively, and said plurality of paralleltunnels are formed in said plurality of receiving tubes.

Preferably, the hollow longitudinal body is a hollow cylindrical body,and the tube holder is a cylindrical tube holder, wherein each of thetwo ends of the hollow cylindrical body comprises an enlarged openinghaving a diameter equal to an outer diameter of said cylindrical tubeholder; and the hollow cylindrical body comprises a regular openingbetween the two ends of the hollow cylindrical body; and a vertical wall(a step) at the interface of the enlarged opening and the regularopening, which is able to stop an insertion of the cylindrical tubeholder into the regular opening of the hollow cylindrical body, whereinan alignment mechanism is provided on each of the ends of the hollowcylindrical body and on the cylindrical tube holder for said pluralityof openings of the two cylindrical tube holders being able to be alignedwith one another when the two cylindrical tube holders are connected totwo ends of the hollow cylindrical body. More preferably, the alignmentmechanism comprises an axial groove formed on a surrounding surface ofthe cylindrical tube holder, and an axial protrusion corresponding tothe axial groove formed on an inner wall of the enlarged opening of theend of the hollow cylindrical body, or vice versa.

Alternatively, the apparatus of the present invention further comprisesa plurality of receiving tubes, wherein said longitudinal body has amulti-tubular structure with a plurality of openings, and said pluralityof receiving tubes are mounted in said plurality of openingsrespectively, so that said plurality of parallel tunnels are formed insaid plurality of receiving tubes.

Preferably, said exit end of said reservoir has an opening having adiameter about equal to a diameter of said longitudinal body. Morepreferably, said exit end of said reservoir has a thinner wall portionhaving an inner diameter equal to an outer diameter of said longitudinalbody, so that one end of said longitudinal body can be plugged into thisthinner wall portion of the exit end of said reservoir.

Preferably, said longitudinal body has a annular structure with an axialopening in said longitudinal direction of said body and said pluralityof parallel tunnels being formed circumferentially around said axialopening, and said exit end of said reservoir has an annular openingcorresponding to said annular structure and in fluid communication withsaid plurality of parallel tunnels. Alternatively, said longitudinalbody has a annular structure and an axial dome protruding from aproximal end of the annular structure, wherein said plurality ofparallel tunnels are formed circumferentially and around said axial domeof said longitudinal body, and said exit end of said reservoir isleak-tightly connected to said proximal end of said annular structure toform an annular opening around said axial dome and in fluidcommunication with said plurality of parallel tunnels. Said annularopening of said reservoir has a radial distance about equal to a radialthickness of said annular structure.

Preferably, the apparatus of the present invention further comprises anair-penetrable film being provided to cover one end of said longitudinalbody, so that air in said plurality of parallel tunnels is pushed out bysaid filler and said filler is retained in said plurality of paralleltunnels, when said filler contained in said reservoir is driven intosaid plurality of parallel tunnels by said driving means.

Preferably, said reservoir comprises a cylindrical container forreceiving said filler, and said driving means is a dispensing plungerslidably received in said cylindrical container, so that the fillercontained in said cylindrical container is able to be pushed by theplunger into said plurality of parallel tunnels via said exit end.

The present invention also discloses a method for simultaneously fillinga filler in a plurality of parallel tunnels, said method comprisingdriving a filler contained in a reservoir into said plurality ofparallel tunnels via an exit end of said reservoir, wherein said exitend is in fluid communication with said plurality of parallel tunnels,and the cross-sectional area of said exit end is less than about 5 timesof a total cross-sectional area of said plurality of parallel tunnels.

Preferably, said plurality of parallel tunnels in the aforesaid methodof the present invention are the plurality of parallel tunnels of theaforesaid filling apparatus of the present invention.

Preferably, said reservoir comprises a cylindrical container forreceiving said filler, and a dispensing plunger slidably received insaid cylindrical container is pressed to push the filler contained insaid cylindrical container into said plurality of parallel tunnels viasaid exit end. Preferably, said filler is cement paste.

The present invention further provides a method of injecting filler intoa site comprising the following steps: a) providing a fillersimultaneously filled in a plurality of parallel tunnels; b) introducingthe filler in said tunnel into a tube with one end thereof in said siteand another end thereof in fluid communication with said tunnel; c)removing said tunnel from said tube after said filler in said tunnelbeing at least partially introduced into said tube in step b); and d)optionally repeating step b) and step c) by using another tunnel filledwith said filler in step a) until a desired amount of filler is injectedinto said site.

Preferably, said providing a filler simultaneously filled in a pluralityof parallel tunnels in step a) is accomplished by the aforesaid methodfor simultaneously filling a filler in a plurality of parallel tunnelsof the present invention.

Preferably, step b) comprises connecting one end of said tunnel to saidanother end of said tube, so that said one end of said tunnel is influid communication with said another end of said tube; and pushing saidfiller in said tunnel from another end thereof. More preferably, saidpushing comprises inserting a plunger into said another end of saidtunnel and pressing said plunger to move from said another end of saidtunnel to said one end of said tunnel.

Preferably, step b) comprises connecting said tunnel to said tube byreceiving said another end of said tube in one end of said tunnel; andpressing another end of said tunnel with the filler entrapped therein tomove from said another end of said tube toward said one end of saidtube, wherein an air-penetrable film is provided to cover said anotherends of said plurality of parallel tunnels, so that the filler entrappedin each of said plurality of parallel tunnels is delivered from saidtunnel into said tube.

Preferably, said plurality of parallel tunnels are formedcircumferentially in a longitudianl body, and step c) comprisesrevolving said longitudianl body after said filler in said tunnel beingat least partially introduced into said tube in step b), so that anothertunnel filled with said filler adjacent to the at least partially emptytunnel is aligned to said another end of said tube.

Preferably, said site is a bone cavity, and said filler is cement paste.

In one of the preferred embodiments of the present invention a systemfor filling a cavity (preferably, but not limited to, a bone cavity) isdisclosed, which comprises:

-   -   (a) a powder component;    -   (b) a liquid component;    -   (c) a mixing mechanism for mixing said powder and said liquid;    -   (d) a container (reservoir) for collecting the mixed cement        paste;    -   (e) a receiver comprising multiple dispensing units, e.g.        tunnels, tubes or partitioning openings, wherein an exit end of        the container is adapted to be attached to a receiver, and a        piston inserted from an entrance end of the container can push        the mixed cement paste into the receiver, that is the mixed        cement paste pushed by the piston can simultaneously flow into        each dispensing unit; and    -   (f) optionally, a surgical tube to be inserted into a cavity.

Advantages over conventional syringe devices:

-   -   (i) The difference between the cross-sectional area of the        container (reservoir) and the total cross-sectional area of the        exit is dramatically reduced, thereby greatly reducing the        pressure required to push the cement paste out of the exit.    -   (ii) A more viscous cement paste can be delivered, resulting in        better performance of the hardened cement paste.    -   (iii) The undesired liquid-powder separation phenomenon is        largely eliminated, resulting in a more uniform distribution in        liquid-powder ratio and cement paste properties throughout the        entire delivery procedure.    -   (iv) The elimination of liquid-powder separation guarantees a        better cement paste delivery efficiency (percentage of the        cement paste that can be uniformly transported through the thin        tube).    -   (v) Delivery of a highly viscous cement paste through a thinner        (than conventionally used) tube becomes possible.    -   (vi) The simultaneous flow of the cement paste into multiple        dispensing units largely reduces the delivery time, thereby        increasing the reliability (decreasing the risks) of the        procedure.

In the following description, for purposes of explanation, specificnomenclature is set forth to provide a thorough understanding ofembodiments of the present invention. It will be apparent to one skilledin the art that specific details in the description may not be requiredto practice the embodiments of the present invention.

Powder Component

The powder component, that is able to form a cement paste while mixingwith a liquid component (a setting solution), may be prepared from anybiocompatible material, such as a calcium-based material (calciumphosphate, calcium sulfate, etc.), polymer-based material (PMMA,biodegradable polymer, etc.), bioactive glass, or drug/growthfactor-carrying microbeads.

Liquid Component

The liquid component can be any setting solution that is able to form acement paste while mixing with the powder component. The liquid can be awater-based, oil-based or polymer-based liquid.

Mixing Mechanism

The mixing mechanism can be any commonly known manual mixing orautomatic mixing mechanism. The mixing can be carried out through movingblades, pressurized air stirring, ball-mill mixing, grinding mixing, orcontainer shaking/rotating. The automatic mixing can be activatedelectrically or by vacuum/pressure activation.

Container (Reservoir)

The container can be of any shape, depending on application andfabrication conveniences. The container, which is preferably, but notlimited to, cylindrical-shaped (similar to a regular syringe, except theexit end with a special design), is for collecting the mixed cementpaste. An exit end of the container is attached to a receiver. A pistoncan be inserted from an entrance (paste-receiving) end of the container,pushing the cement paste into the receiver by thumb or any commondevice. For the conveniences of most clinical applications, typically,the container has an inner diameter from about 10 mm to about 50 mm anda length from about 50 mm to about 150 mm.

Receiver

Three different types of receivers are disclosed: (1) “tunnel-type”receiver; (2) “tube-type” receiver; and (3) “annular-type” receiver.However, others can also be designed with the same principle and spirit.

Tunnel-Type Receiver

As shown in FIG. 1, this type of receiver 10 has a cylindricallongitudinal body 11 and a plurality of parallel tunnels 12 formed inthe longitudinal body. The longitudinal body 11 has a multi-tubularstructure with the plurality of parallel tunnels 12 being so compactsuch that as many parallel tunnels 12 as possible are formed. The uniquedesign of the tunnel-type receiver allows the mixed cement paste pushedby the piston from the container to simultaneously flow into eachdispensing tunnel. The cement pastes filled in the tunnels are readilyto be injected into a bone cavity one at a time via a surgical tubewhich has an outer or inner diameter about equal to the inner diameterof the tunnel. This design dramatically reduces the cement pastedelivery time, which is critical due to the limited working time of thecement paste, especially for minimally invasive procedures that requirea very thin tube to be percutaneously inserted into a bone cavity.

Furthermore, this inventive design dramatically reduces the differencebetween the cross-sectional area of the container (reservoir) and thetotal cross-sectional area of all the tunnels, thereby greatly reducingthe pressure required to push the cement paste out of the exit of thecontainer. For a more satisfactory result, the cross-sectional area ofthe container (the exit end) is preferably less than 3 times of thetotal cross-sectional area of all the tunnels; more preferably less than2 times of the total cross-sectional area of all the tunnels. As acomparison, the cross-sectional area of the container of a conventional10 c.c. syringe is larger than that of its exit by about 60 times; andthe cross-sectional area of the container of a conventional 20 c.c.syringe is larger than that of its exit by about 100 times. Thedifference between the cross-sectional area of the container (reservoir)and the cross-sectional area of all the tunnels in the tunnel-typereceiver of the present invention is dramatically reduced, which in turngreatly increases the cement paste delivery efficiency and reduces thesolid-liquid separation effect that largely hinders the delivery of thecement paste, as mentioned above.

The tunnel-type receiver is preferably, but not limited to,cylindrical-shaped, and preferably has a similar shape as the container.The receiver has a diameter from about 10 mm to about 50 mm and a lengthfrom about 50 mm to about 150 mm. The tunnels running through thereceiver and parallel to the longitudinal axis of the cylindrical bodyhave a substantially same diameter. Each individual tunnel has adiameter from about 1 mm to about 3 mm, depending on the application.The tunnels are as “close-packed” as possible, so that the difference inthe cross-sectional area of the container and the total cross-sectionalarea of all the dispensing tunnels may be minimized.

As shown in FIG. 2, a connector 91 leak-tightly connects the exit end 21of the container 20 to a proximal end 19 of the tunnel-type receiver 10,so that the exit end 21 is in fluid communication with the plurality ofparallel tunnels 12. Depending on how the two components are fastened,the following three options are possible: (1) the inner diameter of theexit end 21 is equal to the outer diameter of the longitudinal body 11;(2) the outer diameter of the exit end 21 is equal to the outer diameterof the longitudinal body 11; or (3) the outer diameter of the exit end21 is slightly smaller than the outer diameter of the longitudinal body21. A perforated cap 92 is mounted to a distal end of the receiver 10 tofasten an air-penetrable film 93 between the perforated cap 92 and thereceiver 10, so that air in said plurality of parallel tunnels 12 ispushed out by the cement paste 80 and the cement paste 80 is retained bythe air-penetrable film 93 in said plurality of parallel tunnels 12,when said cement paste 80 contained in said container 20 is driven intosaid plurality of parallel tunnels 12 by the piston 70. Optionally, thetunnel may be slightly enlarged at the proximal end 19 (diameter isincreased at the end of the tunnel) to more easily allow the cementpaste to flow into the tunnel and be pushed into a surgical tube (orconnecting tube). The receiver can be made from any medical-grademetallic or polymeric material, for example, stainless steel, PU, PP,PE, Teflon®, etc., having sufficient strength as not to bend when afiller is driven simultaneously into said parallel tunnels. The tunnelsmay be prepared from any commonly known method, e.g., mechanicaldrilling, laser drilling, extrusion, injection molding, etc.

As shown in FIG. 3, a connector 94 is used to leak-tightly connect thesurgical tube 61 and the connecting tube 62, when one end of thesurgical tube 61 is percutaneously inserted into a bone cavity and theremaining portion thereof is not long enough for directly delivering thecement paste from the tunnels without a plunger. The tunnel 12 has aninner diameter slightly greater than the outer diameter of the surgicaltube 61 or the connecting tube 62, and is coupled to the other end ofthe surgical tube 61 (or connecting tube 62). The receiver 10 is pushedtoward the surgical tube 61 or the connecting tube 62, which slides inthe cement paste filled tunnel 12, and most of the cement paste 80 isnow transferred from the tunnel 12 into the surgical tube 61 or theconnecting tube 62 with the pushed end closed either by the cap 92 andthe film 93 or by a finger. The cement pastes 80 filled in the tunnels12 thus can be directly pushed into the surgical tube 61 (or connectingtube 62), one at a time, until a desired amount of cement paste isdelivered into the bone cavity via the surgical tube and optionally theconnecting tube.

Alternatively, the cement pastes 80 filled in the tunnels 12 may bepushed into the surgical tube 61 (or connecting tube 62), one at a time,by a plunger 71, as shown in FIG. 4.

Tube-Type Receiver

As shown in FIGS. 5 and 6, the receiver 10 may be a hollow body 11′(similar to a pipe), preferably has a cylindrical shape, similar to thetunnel-type receiver. The hollow cylindrical body 11′ encloses multiplereceiving tubes 12′ running parallel to the longitudinal axis of thehollow cylindrical body 11′, wherein the mixed cement paste 80 pushedfrom the piston 70 can simultaneously flow into each receiving tube 12′.The receiving tubes 12′ are preferably close-packed in the hollowcylindrical body 11′, so that the difference in the cross-sectional areaof the container 20 and the total cross-sectional area of all thereceiving tubes may be minimized. Similar to the tunnel-type receiver aconnector 91 leak-tightly connects the exit end 21 of the container 20to a proximal end 19 of the tube-type receiver 10, so that the exit end21 is in fluid communication with the plurality of receiving tubes 12′.A perforated cap 92 is mounted to a distal end of the receiver 10 tofasten an air-penetrable film 93 between the perforated cap 92 and thereceiver 10 to avoid air accumulation in the receiving tubes 12′ and toavoid the cement paste leaking from the receiver 10, when the cementpaste 80 is pushed by the piston 70 to simultaneously flow into eachreceiving tube 12′. Alternatively, the hollow cylindrical body 11′ maybe replaced by a cylindrical body having a multi-tubular structuresimilar to the cylindrical longitudinal body 11 shown in FIG. 1, and thereceiving tubes 12′ are slidably received in the plurality openings ofthe multi-tubular structure so that the cement paste 80 can be pushed bythe piston 70 to simultaneously flow into each receiving tube 12′. It isapparent that the tunnels 12 in the tunnel-type receiver as shown inFIG. 1 are now the longitudinal holes in the receiving tubes 12 as shownin FIG. 5.

The tube-type receiver is preferably, but not limited to,cylindrical-shaped, and preferably has a similar shape as the container.The hollow cylindrical body 11′ has a diameter from about 10 mm to about50 mm and a length from about 50 mm to about 150 mm. Each individualreceiving tube 12′ has an inner diameter from about 1 mm to about 3 mm,depending on the application.

The tube-type receiver and the tunnel type receiver are similar inconstruction and function; however, each individual receiving tube 12′in the tube-type receiver after simultaneously filled with the cementpaste can be taken out from the hollow cylindrical body 11′ and appliedseparately. Accordingly, more than one bone cavities can besimultaneously injected with the cement paste, when the tube-typereceiver is used.

The individual receiving tube 12′ filled with cement paste can becoupled to a surgical tube 61 directly, or via a connecting tube, or viaan extension tube 63 and a connecting tube 62 as shown in FIG. 7,wherein the inner diameter of the receiving tube 12′ is slightly greaterthan those of the surgical tube 61, connecting tube 62, and extensiontube 63. The cement paste in the receiving tube 12′ is then transferredinto the surgical tube 61 directly or indirectly without a plunger asdescribed in the aforesaid tunnel-type receiver case (FIG. 3). Thecement pastes 80 filled in the receiving tubes 12′ thus are eventuallyinjected into a bone cavity 100, one at a time, until a desired amountof cement paste is injected.

Alternatively, the cement pastes 80 filled in the receiving tubes 12′may be pushed into the surgical tube 61 (or connecting tube 62), one ata time, by a plunger 71, as shown in FIG. 8, wherein a connector 95 isused to leak-tightly connect the receiving tube 12′ and the surgicaltube 61 (or connecting tube 62). In this case, the receiving tube 12′can have an inner diameter and outer diameter the same as those of thesurgical tube 61 and connecting tube 62. The tube-type receiver can bemade from any medical-grade metallic or polymeric material, for example,stainless steel, PU, PP, PE, Teflon®, etc. and having sufficientstrength as not to bend when a filler is driven simultaneously into saidparallel tunnels. The tubes may be prepared from any commonly knownmethod, e.g., extrusion, injection molding, etc.

Annular Receiver

Alternatively, the receiver may have a annular structure. As shown inFIG. 9, the annular receiver 10 has a longitudinal cylindrical body 11with an axial opening and a plurality of parallel tunnels 12 beingformed circumferentially around said axial opening. The enlarged exitend 21 of the container 20, as shown in FIG. 10, has an annular opening22 corresponding to said annular structure. The receiver diameter istypically larger than the diameter of the container 20. The annularopening 22 of the container 20 has outer and inner diameterssubstantially the same as those of the receiver 10, so that thecontainer 20 and the receiver 10 can be easily connected anddisconnected by a quick connector 24. The mixed paste cement 80 in thecontainer 20 can be pushed by the piston 70 to simultaneously flow intoeach tunnel 12 of the receiver 10, when they are connected. Anair-penetrable film 93 is used to cover tunnels 12 from the lower end ofthe receiver 10, so that air will not be trapped in the tunnels 12, andthat no excess cement paste is leaked from the tunnels 12. To moreefficiently transport the mixed cement paste 80 from the container 20into the donut-shaped receiver 10, the piston 70 slidably received inthe container 20 preferably has a substantially concave down dome shape.

The annular receiver 10 has an outer diameter from about 20 mm to about100 mm, an inner diameter from about 10 mm to about 90 mm, and a lengthfrom about 10 mm to about 100 mm. Each tunnel 12 has a diameter fromabout 1 mm to about 3 mm, depending on the application. The tunnels 12in the longitudinal cylindrical body 11 are as “close-packed” aspossible, so that the difference in the cross-sectional area of theannular opening 22 of the container 20 and the total cross-section areaof all the tunnels 12 of the receiver 10 may be minimized. For a moresatisfactory result, the cross-sectional area of the annular opening 22of the container 20 is preferably less than 3 times, and more preferablyless than 2 times of the total cross-sectional area of all the tunnels12 of the receiver 10.

Alternatively, the longitudinal body 11 of the annular receiver 10 hasan axial dome 13 protruding from a proximal end of the annularstructure, wherein the plurality of parallel tunnels 12 are formedcircumferentially and around said axial dome 13 of said longitudinalbody 11, and the enlarged exit end 21 of the container 20 isleak-tightly connected to said proximal end of said annular structure toform an annular opening 22 around said axial dome 13 and in fluidcommunication with said plurality of parallel tunnels 12, as shown inFIGS. 11 and 12.

A unique advantage for the donut-receiver design is that the receiver 10(cartridge 10) can be easily and quickly attached to a “gun” device 50and the cement paste in each tunnel of the cartridge can be injectedautomatically or semi-automatically by the gun device as shown in FIG.13. In this gun-type deliverer design, a plunger 71 is incorporated topush the cement paste out of each tunnel. The plunger has a diameterslightly smaller than the diameter of the tunnel, so that the plungermay go in and out the tunnel smoothly. The plunger may be insertedpartly or all the way into each tunnel of the cartridge. The linearmovement of the plunger may be driven by any common mechanism.

The gun device 50 further comprises a mechanism to drive the cartridge10 to rotate about the longitudinal axis of the cartridge, so that,after each stroke, the cartridge 10 rotates to a new position where thefollowed-up tunnel is in alignment with the plunger 71 and the surgicaltube 61 (or connecting tube 62). The rotation of the cartridge can bedriven by any common mechanism. This injection/rotation movement isrepeated and the cement paste is injected out of each tunnel, one afteranother, until a desired amount of paste is delivered out of thecartridge.

The annular receiver can be made from any medical-grade metallic orpolymeric material, for example, stainless steel, Teflon®, PP, PE, PU,etc. The multiple tunnels of the cartridge may be prepared from anycommonly known method, e.g., machining, mechanical drilling, laserdrilling, extrusion, and injection molding, etc.

According to the present invention, after all tunnels (for thetunnel-type receiver and annular receiver), and receiving tubes (for thetube-type receiver) are filled with paste, the receiver is disconnectedfrom the container. The paste-exposing end (the end attached to thecontainer exit) is then used as the front-end (the end approaching thesurgical tube or the connecting tube, depending on the application),while delivering the cement paste into the surgical tube or connectingtube.

The surgical tube suitable for use in the present invention is a tube tobe inserted into the cavity to facilitate delivery of the cement paste.For minimally invasive procedures, the surgical tube is preferably asmall-diameter, thin-walled tube that may be percutaneously insertedinto a bone cavity with minimal wounds. The surgical tube has an innerdiameter from about 1 mm to about 3 mm, and a length from about 50 mm toabout 250 mm, depending on the application. The surgical tube ispreferably made from a high strength, medical-grade metal such asstainless steel, and titanium alloys, etc. The surgical tube may bemanufactured by any common methods. Preferably a thin rod with a sharphead to facilitate drilling or hammering is enclosed in the surgicaltube. After an opening is created by the drilling or hammering, the thinrod is retrieved and the surgical tube is left in the cavity. If thesurgical tube is sufficiently long, the cement paste filled in eachtunnel or tube may be directly transported into the surgical tube.

The connecting tube (preferably made from, but not limited to, abendable, polymeric material, for example, PU, PP, PE, and Teflon®,etc.) used in the present invention is incorporated to connect thetunnel or receiving tube filled with cement paste and the surgical tube.In this case the paste in each tunnel or receiving tube is transferredinto the connecting tube and later pushed into the surgical tube by thefollowed-up cement paste.

The extension tube used in the present invention (preferably made from abendable, polymeric material, for example, PU, PP, PE and Teflon®, etc.)is further incorporated to connect the connecting tube and the surgicaltube. The use of this extension tube is to keep surgeon's hands fartherfrom the x-ray-guided surgical site as well as for the surgeon to moreeasily handle the apparatus during the operation. In this case the pastein each tunnel (or receiving tube) is first transferred into theconnecting tube, followed by the extension tube, and eventually thesurgical tube, one tunnel (or receiving tube) after another, the cementpaste is delivered all the way into the cavity through the surgical tubeby the followed-up cement paste.

The surgical tube, connecting tube and extension tube have substantiallythe same internal diameter. Preferably, a plunger with a diameterslightly smaller than the internal diameter of the surgical tube,connecting tube and extension tube is provided, that is able toclear/push the cement paste remaining in any parts of the tubes into thecavity.

A modified tunnel-type receiver 10 is shown in FIG. 14, which contains ahollow cylindrical body 11′, four horizontal partition boards 11 h andfour vertical partition boards 11 v. The horizontal partition boards 11h and the vertical partition boards 11 v all have half-way throughslits, by which they are engaged with each other to form a divided wallstructure 11″. The divided wall structure 11″ is plugged into the hollowcylindrical body 11′ to form modified tunnel-type receiver 10.

In FIG. 15 a modified tube-type receiver 10 is shown, which contains ahollow cylindrical body 11′, two cylindrical tube holders 14, and aplurality of receiving tubes 12′. Two axial grooves 141 are formed on asurrounding surface of the cylindrical tube holder 14, and two axialprotrusions 111 corresponding to the axial grooves 141 are formed on aninner wall of the enlarged opening of the end of the hollow cylindricalbody 11′. The two cylindrical tube holders 14 are mounted in the twoends of the hollow cylindrical body 11′ with the axial grooves 141 beingengaged with the axial protrusions 111, thereby the openings 15 of thetwo cylindrical tube holders 14 are aligned with one another, and thenthe receiving tubes 12′ are received in the openings 15 of the twocylindrical tube holders 14 respectively. Each of the two ends of thehollow cylindrical body 11′ has an enlarged opening having a diameterequal to an outer diameter of said cylindrical tube holder 14, wherein aregular opening is between the two ends of the hollow cylindrical body11′, and a vertical wall is at the interface of the enlarged opening andthe regular opening, which is able to stop an insertion of thecylindrical tube holder 14 into the regular opening of the hollowcylindrical body 11′. The exit end 21 of the container 20 has a thinnerwall portion (an enlarged opening) so that a proximal end 19 of themodified tube-type receiver 10 can be plugged into this thinner wallportion of the exit end 21 of the container 20, and so that the exit end21 of the container 20 is in fluid communication with the plurality ofreceiving tubes 12′ mounted in the openings 15 of the two cylindricaltube holders 14. A perforated cap 92 is mounted to a distal end of thereceiver 10 to fasten an air-penetrable film 93 between the perforatedcap 92 and the receiver 10 to avoid air accumulation in the receivingtubes 12′ and to avoid the cement paste leaking from the receiver 10,when the cement paste 80 in the container 20 is pushed by the piston 70to simultaneously flow into each receiving tube 12′.

FIG. 16 shows another modified tube-type receiver 10, wherein eightreceiving tubes 12′ are received in the openings 15 of two rolls of⅛-sector-divided cylindrical tube holders 14, which can then be rolledup and plugged into a hollow cylindrical body 11′ to form the tube-typereceiver 10.

The receiver of the present invention is not necessarily cylindrical. Asshown in FIGS. 17 and 18, the receiver 10 has a hollow body 11′ whichhas a circular rear end and a square front end, a rear tube holder 14 rwith two axial grooves 141 plugged into the circular rear end, and afront tube holder 14 f plugged into the square front end. The rear tubeholder 14 r and the front tube holder 14 f both have eight openings 15which are identical and aligned with one another, so that eightreceiving tubes 12′ can be received in the openings 15 to form atube-type receiver 10. This tube-type receiver 10 has a circular rearend which is able to be connected to a cement paste container forfilling the cement paste into the receiving tubes 12′ as in the otherembodiments of the present invention described above. An outlet adapter51 is capped onto the square front end of the receiver 10 to facilitatethe delivery of cement pastes filled in the eight receiving tubes 12′.The outlet adapter 51 is formed with a track defining eight stops 52corresponding to eight receiving tubes 12′ received in the eightopenings 15 of the square front tube holder 14 f, and a cement outlet 53can be pushed to slide into and out from the eight stops 52 in the trackone after another, whereby the cement paste filled in the receivingtubes 12′ can be alternatively pushed out by a plunger into a surgicaltube or a connecting tube via the cement outlet 53.

An outlet adapter 51 with a ratchet mechanism for delivering the cementpaste in the receiver 10 is shown in FIG. 19. The outlet adapter 51 hasa rotating seat 54, and the receiver 10 is rotatably received therein bythe conventional spindle/round hole structure. The receiver 10 isprovided with ratchet teeth 55 on its surface corresponding to theparallel tunnels 12 or receiving tubes 12′ of the receiver 10, and therotating seat 54 is provided with two detents 56 on its inner wall toengage with the ratchet teeth 55, so that the receiver 10 is only ableto be rotated in one direction (counterclockwise). The rotating base 54is provided with two axial holes which are in alignment with a paralleltunnel 12 or a receiving tube 12′ of the receiver 10 when the detents 56contact vertical walls of two of the ratchet teeth 55, and the rotatingbase 54 is further provided with a cement outlet 53 on one of the twoaxial holes, so that a plunger inserting into the other axial hole canpush the cement paste filled in the parallel tunnel 12 or the receivingtubes 12′ into a surgical tube or a connecting tube via the cementoutlet 53. Accordingly, the cement paste in all the parallel tunnels 12or receiving tubes 12′ of the receiver 10 can be delivered one-by-one byratcheting the receiver 10 in the rotating base 54.

An outlet adaptor 51 with sealing and blocking mechanism for deliveringthe cement paste in the receiver 10 is shown in FIG. 20. The outletadaptor 51 is formed with a cement outlet 53 at one side thereof and isrotatably connected to one end of the receiver 10 at another sidethereof. The outlet adaptor 51 at the another side thereof is furtherprovided with an O-ring 57 surrounding an opening of the cement outlet53, a plurality of recesses, and a plurality of balls 58 received in theplurality of recesses, as shown in (a) In FIG. 20. The O-ring 57 assuresthat the cement outlet 53 and one of the receiving tubes 12′ is inleak-tightly fluid communication with each other, while the balls 58leak-tightly block the remaining receiving tube 12′ of the receiver 10.Another similar outlet adaptor 51 is shown in (b) in FIG. 20, whereinthe balls 58 in FIG. 20( a) are replaced with elastomer plugs 58′. Stillanother similar outlet adaptor 51 is shown in (c) in FIG. 20, whereinthe recesses and the balls 58 in FIG. 20( a) are replaced with chamferedcylindrical plugs 58″ integrally formed with the outlet adaptor. Theoutlet adaptors 51 shown in (a) to (c) in FIG. 20 can avoid the cementpaste filled in the receiving tubes 12′ from leaking when it isdelivered from the receiving tubes 12′ to a surgical tube or aconnecting tube via the cement outlet 53 alternately.

A wave-like tack 591 can be formed around the surface of the receiver 10as shown in FIG. 21. A pair of sliding guides 592 are formed oppositelyon an inner wall of the outlet adaptor 51, which are received in thewave-like tack 591, so that the outlet adaptor 51 can move up and downwhen the outlet adaptor 51 is turned. The outlet adaptor 51 is formedwith a cement outlet 53 at the outer side thereof, and at the oppositeside thereof is further provided with O-rings 57 corresponding thereceiving tubes 12 of the receiver 10, wherein one of the O-rings 57surrounds an opening of the cement outlet 53. By the engagement of thesliding guides 592 and the wave-like tract 591, the O-rings 57 will bepressed by the tube holder 14 of the receiver 10, when the outletadaptor 51 is turned to move down on the receiver 10; and the O-rings 57will move frictionlessly, when the outlet adaptor 51 is turned to moveup on the receiver 10. As a result, the cement paste filled in thereceiving tubes 12′ can be transported alternately into a surgical tubeor connecting tube via the cement outlet 53 without leaking.

Although the present invention has been described with reference tospecific details of certain embodiments thereof, it is not intended thatsuch details should be regarded as limitations upon the scope of thepresent invention. Many modifications and variations are possible inlight of the above disclosure.

1. A filling apparatus comprising a plurality of parallel tunnels formedin a longitudinal body and in a longitudinal direction of said body;said body being straight and having sufficient strength as not to bend;a filler reservoir having an exit end adapted to be in fluidcommunication with said plurality of parallel tunnels, wherein across-sectional area of said exit end is less than about 5 times of atotal cross-sectional area of said plurality of parallel tunnels.
 2. Theapparatus of claim 1, wherein said tunnels have an inner diameter ofabout 1 mm to about 10 mm, and a length of about 10 mm to 300 mm.
 3. Theapparatus of claim 1, wherein the cross-sectional area of said exit endis less than about 3 times of a total cross-sectional area of saidplurality of parallel tunnels.
 4. The apparatus of claim 1, wherein thecross-sectional area of said exit end is about 1.5 to about 1.1 times ofa total cross-sectional area of said plurality of parallel tunnels. 5.The apparatus of claim 1, wherein said longitudinal body has amulti-tubular structure with said plurality of parallel tunnels beingformed therein.
 6. The apparatus of claim 1 further comprising aplurality of receiving tubes, wherein said longitudinal body is a hollowlongitudinal body and said plurality of receiving tubes are received insaid hollow longitudinal body such that said plurality of paralleltunnels are formed in said plurality of receiving tubes.
 7. Theapparatus of claim 6 further comprising two tube holders, wherein eachof the two tube holders comprises a multi-tubular structure with aplurality of openings, and the two tube holders are connected to or oneof them is connected to and the other one is adapted to be releasablyconnected or both adapted to be releasably connected to two ends of thehollow longitudinal body with said plurality of openings of the two tubeholders being aligned with one another, such that said plurality ofreceiving tubes are mounted in said plurality of openings of the twotube holders respectively, and said plurality of parallel tunnels areformed in said plurality of receiving tubes.
 8. The apparatus of claim 1further comprising a plurality of receiving tubes, wherein saidlongitudinal body has a multi-tubular structure with a plurality ofopenings, and said plurality of receiving tubes are mounted in saidplurality of openings respectively, so that said plurality of paralleltunnels are formed in said plurality of receiving tubes.
 9. Theapparatus of claim 5, wherein said exit end of said reservoir has athinner wall portion having an inner diameter equal to an outer diameterof said longitudinal body, so that one end of said longitudinal body canbe plugged into this thinner wall portion of the exit end of saidreservoir.
 10. The apparatus of claim 6, wherein said exit end of saidreservoir has a thinner wall portion having an inner diameter equal toan outer diameter of said longitudinal body, so that one end of saidlongitudinal body can be plugged into this thinner wall portion of theexit end of said reservoir.
 11. The apparatus of claim 1, wherein saidlongitudinal body has an annular structure with an axial opening in saidlongitudinal direction of said body and said plurality of paralleltunnels being formed circumferentially around said axial opening, andsaid exit end of said reservoir has an annular opening corresponding tosaid annular structure and in fluid communication with said plurality ofparallel tunnels.
 12. The apparatus of claim 1, wherein saidlongitudinal body has an annular structure and an axial dome protrudingfrom a proximal end of the annular structure, wherein said plurality ofparallel tunnels are formed circumferentially and around said axial domeof said longitudinal body, and said exit end of said reservoir isleak-tightly connected to said proximal end of said annular structure toform an annular opening around said axial dome and in fluidcommunication with said plurality of parallel tunnels.
 13. The apparatusof claim 1 further comprising a driver for driving the filler containedin said reservoir into said plurality of parallel tunnels via said exitend.
 14. The apparatus of claim 13 further comprising an air-penetrablefilm being provided to cover one end of said longitudinal body, so thatair in said plurality of parallel tunnels is pushed out by said fillerand said filler is retained in said plurality of parallel tunnels, whensaid filler contained in said reservoir is driven into said plurality ofparallel tunnels by said driver.
 15. The apparatus of claim 13, whereinsaid reservoir comprises a cylindrical container for receiving saidfiller, and said driver is a dispensing plunger slidably received insaid cylindrical container, so that the filler contained in saidcylindrical container is able to be pushed by the plunger into saidplurality of parallel tunnels via said exit end.
 16. The apparatus ofclaim 1, wherein the filler reservoir has a volume for containing afiller close to or greater than a total volume of said plurality oftunnels, so that said plurality of tunnels are able to be filled withthe filler in the filler reservoir.